Arduino IDE on macOS Big Sur

A couple days ago I got my new MacBook Pro with M1 Chip and yesterday I tried to install the Arduino IDE to Flash some ESP2866 Chips. Unfortunately, this did not work.

I was able to install and run the Arduino IDE without any problems. The problem was that I could not flash a program to an ESP2866. The error was the following:

pyserial or esptool directories not found next to this

So I checked if the folders or files were there and they were. I wasn't sure what the problem was so I searched the internet and found that these files are probably too old for Big Sur. The fix is to download a newer version of pyserial and esptool and replace the old ones.


Extract both zip Files and rename it to: pyserial and esptool. Now you can copy both directories to:


and overwrite the old files.

After that you have to restart the Arduino IDE and the flashing should work again.